Following World War I, Romania experienced a serious increase in size and power. During the interwar period, Romania was an important exporter of raw materials, first of all grains, corn, oil and timber. When it came to oil exports it was second, only behind the USSR in Europe, and sixth in the world.
During World War I, the oil field installations were destroyed by sabotage, and were partially rebuilt by Germany between 1916 and 1918. Their rehabilitation continued after the war and was finished around 1924.
Between 1918 and 1924, 101 new companies were registered in Romania, most of them with Romanian capital, whose activity was the extraction, transformation or distribution of crude oil and/or its derivatives. Some of them – like the Creditul Minier, Industria Romana de Petrol (known as IRDP), and Pacura Romaneasca were quite important, while other ones were small enterprises. In 1920 when the Romanian state, through its Liberal government, offered state monopoly-like concession to the IRDP, diplomats of England, the USA, France and the Netherlands exercised serious pressure, even threatening with retrieval of international loan for rebuilding the country from London’s financial markets. The government had to give up the idea.

Among foreign investments, the English was the most important one, and replaced in a successful way former German and Austro-Hungarian interests. The most important company was the British-Dutch Royal Dutch-Shell, through its affiliated branch-company, the Astra Română. In 1920 other English companies penetrated the Romanian market, like the Anglo-Persian oil Co Ltd., through the Steaua Română (having previously German capital), the Sospiro Oilfields, and the Phoenix Oil and Transport Co. Ltd.
As a result of peace treaties, French capital received equal share with British one from former interests of German and Austro-Hungarian firms. Just as British investors cooperated with Dutch ones, the French cooperated with Belgians. The most important representative of French-Dutch capital was the cartel-like company "Omnium International des Petroles", with its headquarter in Paris. Among its stockholders were firms like "Banque de Paris et des Pays Bas - Paribas", Banque "Mirabaud et Co.", "Louis Hirsch et Co.", "Petroles des Roumanie-Anvers" - its main branch company in Romania was the Colombia, founded in 1920. Other companies with French or Belgian interests were the "Petrol Block", "Aquila Franco-Romana" and "Compagnie Financiere Belge des Petroles".

American capital missed the opportunity of redistributing “war prey” (investments of Central Powers) between British, French and Romanian capitals. Instead, the Standard Oil invested in the already existing Romano-Americana company, in which it was the only shareholder. The Romano-Americana quickly became the second major oil producer company after the Astra Romana. US diplomats in general were very active in promoting economic interests from American investors.
Italian capital entered Romania during the mid-twenties, through the AGIP, whose base was in the Prahova valley. Interestingly, unlike England and France, who used refineries on Romanian soil where oil products were transported through pipelines till the port of Constanta, Italians preferred in the mid-thirties to use the AGIP refinery in Fiume. In 1934, Italian authorities asked AGIP to base its supply for the largest part on Romanian oil (around two thirds) leaving the other to short term contracts basically with the Soviet Union. With all this, 1934, exploitation in the Prahova valley declined and Italy never regained its position, facing a far stronger competitor in Nazi Germany. The AGIP often collaborated with American-owned companies, for example, rotary drilling technology was adopted with the help of American engineers.
German direct investments, compared to other ones, were insignificant both under the Weimar Republic and the Nazi Third Reich. On the other hand, Germany in the thirties quickly became the most important partner of Romania when it came to oil import.

In 1938 Germany became Romania´s most important trading partner: 48,5 percent of Romanian imports came from Germany, and 35,9 percent was the share in destination of exports toward Germany. In 1939, the “German-Romanian Treaty for the Development of Economic Relations between the Two Countries” was signed, which granted, for ten years, German primacy in Romanian bilateral trade. The treaty provided German priority in Romanian exports for agricultural, timber and oil products. In exchange Germany granted technical know-how and war equipment. Change could be made through direct exchange, products for products, no use of currency needing to be involved.
The treaty strengthened German economic power considerably and contributed on proving an enhanced economic capability of its war efforts. During World War II, Nazi Germany penetrated the Romanian economy even more, subordinating it to its war objectives.

Germany did not have the petroleum to wage a war of any duration. The basic calculations were stark. The Germans estimated that they needed 12 million tons of oil annually to wage war. The synthetic petroleum industry in the Ruhr based on coal liquidficatioin would by the late 1930s produce about 3 million tons, leaving a defivcit of 9 million tons. Germany could not go to war without a secure source of additional oil. The oil could not be imported by sea because of the Royal Navy. The answer to this shortfall was Romania. The Romanian oil fields centered around Ploesti produced about 7 million tons annually. Romania posed some initial problems because the country had sided with the Allies in World War I and as a result had been rewarded with territorial concessions at the expense of its neighbors which had sided with the Central Powers. The Romanian royal family was a German family, but Romania had sided with the Allies in World War I. Romania agreed to sell most of its oil to Germany (1939). British efforts to bid for the oil failed. The Nazis next convinced the Romanians to expel British technicians (July 1940). General Ion Antonescu, who had been the Minister of War, for King Carol when he seized power (September 6, 1940). This meant that the Nazis had essentially turned Romanian into a satellite state and ally.

Operation Tidal Wave was an air attack by bombers of the United States Army Air Forces (USAAF) based in Libya on nine oil refineries around Ploiești (located ~56 km north of Bucharest - capital city of Romania), on 1 August 1943, during World War II. It was a strategic bombing mission and part of the "oil campaign" to deny petroleum-based fuel to the Axis. The mission resulted in "no curtailment of overall product output", and so was deemed unsuccessful.

This mission was one of the costliest for the USAAF in the European Theater, with 53 aircraft and 660 aircrewmen lost. It was the worst loss ever suffered by the USAAF on a single mission, and its date was later referred to as "Black Sunday". Five Medals of Honor and numerous Distinguished Service Crosses were awarded to Operation Tidal Wave crew members.

Two thousand years ago, oil from seeps was exploited in the Roman province of Dacia, where it was called picula. The first attestation of Oil exploitation in Romania dates from the II century a.d. and continues in the next centuries, being proven by the numerous potteries with marks of crude oil on them, dated in the II-XVI centuries.
The first document from the Romanian historical province of Moldavia regarding fuel oil is dated October 4th 1440, while the first records mentioning oil from Wallachia is dated 1517. In the beginning, crude oil exploitation simply meant collection from the shallow pits and ditches in the outcrops of the Sub-Carpathian area. The technique involved digging small holes into the ground, where fuel oil was collected, while the crude oil was channelled through ditches towards a collecting pit.
The beginning of the Romanian petroleum industry dates back to 1769 with the documentation of rudimentary crude oil extraction in Moldavia by Dimitrie Cantemir, a former Prince of Moldavia, who published the account in "Descriptio Moldaviae".

Romania was the first country in the world (1857) with a petroleum production officially registered in the international statistics. „The Science of Petroleum” certifies in 1938 the fact that Romania was the first country in the world with an oil production of 275 tones officially registered in the international statistics. It was followed by the United States in 1859, Italy in 1860, Canada in 1862 and Russia in 1863.

The first processing equipments of petroleum in the world are considered the “oil pumps” from Lucacesti-Bacau, belonging to N. Choss in 1840 and M. Heimsohn in 1844. This were only simple handmade workshops, equipped with rudimentary methods which were using for refining a system similar to the one for obtaining "țuică" (a traditional Romanian spirit that contains 28%-60% alcohol by volume, prepared from plums) in a rustic boiler. Distillation on industrial way starts with the refinery built by Mehedinteanu brothers at the periphery of Ploiesti city, near the South Station, on 174, Buna Vestire Street. The refinery installations were quite primitive, all the equipment being build up from iron or raw iron cylindrical vessels, warmed up directly with wood fire. This equipment was ordered in Germany from Moltrecht company which was building boilers for bituminous shale distillation, and in December 1856 starts the construction of the gas factory from Ploiesti, on the name of Marin Mehedinteanu.

Bucharest was the world’s first city public illuminated with kerosene. The oil offered by Mehedinteanu brothers for public illumination had incontestable properties: colorless and with no smell, burning with a light flame, with a constant intensity and shape, without smoke and without ash or resinous compounds in the wick. This important properties of the product as well as the offer of 335 lei per year for each street lamp had practically excluded all the competition, the other offers which proposed as a fuel the rape or nut oil were taking the costs up to 600 lei per year.

Teodor Mehedinteanu’s offer was approved on the 8-th October 1856 and so Bucharest would have been illuminated with 1000 street lamps. At 1-st April 1857- the date for coming into operation of the contract for the capital illumination - everything was ready and working well.

The concept of sonic drilling technology was born nearly 100 years ago (~1918) when the civil engineer George Constantinesco wrote a treatise for the British Admiralty called the Theory of Sonics.

In 1912, engineer Virgiliu Tacit patented the blow-out preventer, a remote-controlled valve with a piston, which can stand pressures of up to 100 atmospheres. The invention was then taken over by Germany, the Austro-Hungarian empire and Mexico.

In 1931, the engineer A. Dragulanescu, the director of “Steaua Română” Society presented during the “Engineers and Technicians Associations of the Mine Industry Congress” a method of using unique tubage column in the well field. Dragulanescu’s innovations: drilling on right hole, without deviations reductions of the column number etc. concurred to the same economical saving of 50% drilled linear meters.

Dr. Eng. Ion Basgan the one that using the sonicity principle have licensed in 1934 in Romania and USA a new drilling system: “Method for improving the efficiency and perfecting the rotative drilling through percussive rotation and hydrodynamic pressure absorption.” Basgan procedure had made a fulminant carrier in USA being used in Romania too after 1944 without its merits being recognized.

Lazăr Edeleanu elaborated in 1907 a method of kerosene refining and later other oil products too, through selective refinement, using liquid sulphur dioxide.
Since 1910 Edeleanu himself settled in Germany there he founded a company called "Allgemeine Gesellschaft für Chemische Industrie". Due to the success of the logo "Edeleanu", since 1930 the company changed its name to Edeleanu GmbH. During the National Socialist regime was bought by the Deutsche Erdöl-AG, later changed several times its owners and in 2002 was acquired by Uhde GmbH, which is owned by Thyssen-Krupp trust. The name Edeleanu stayed in use for the refinery department till nowadays.
Lazăr Edeleanu came back to Romania and died in Bucharest in April 1941.

Following World War II, a heavy reconstruction of the petrochemical facilities and expansion was done. Possessing substantial oil refining capacities, Romania is particularly interested in the Central Asia-Europe pipelines and seeks to strengthen its relations with some Arab states of the Persian Gulf. With 10 refineries and an overall refining capacity of approximately 504,000 bbl/d (80,100 m3/d), Romania has the largest refining industry in the region. The refining capacity far exceeds domestic demand for refined petroleum products, allowing the country to export a wide range of oil products and petrochemicals - such as lubricants, bitumen and fertilizers, throughout the region.

and be sure that nobody could know the soul, the oil and the crimes better

and no one could talk to you more brutally than I did.

I, who am black and ugly,
who, like the oil-bearing hills,
have always had something horrible smoldering in my innards,
I, who soil and destroy everything I touch,
who am as foul, fervent and ignorant as oil
and, like it, explode
without caring about the calamity my words bring into the world.
That's me and now I will tell you about oil and its crimes.

Listen:

I still do not know how dirty and black the oil is

and how dirty and black are his men.

Listen:

You know the oil only as pure essence in the test tubes

You do not know like me , thousand murders

and thousand women who were lured

to sell their last piece of land on a night of love

You do not know the false vows and the sordid soul of the oil apprentices,

You do not know the drillers that burned alive in the flame

in the great fires caused by the derricks' owners themselves

to squeeze the last money from insurance companies;

You do not know all this

and you know nothing of oil and its crimes.

But you do not know me either

because all that I have told you so far

is not at all a scream of revolt for the fate of women and the wronged drillers,

but a beginning of the hymn for oil and for his people's atrocities,

a beginning of hymn for those who are able to lie, deceive and steal,

a beginning of hymn for me and all my brothers in infamy.

I do not love oil when the pure essence gets into the test tubes,

I love it so he gets out of the ground: dirty,

I love him with anger, with passion

and I want to glorify my terrible race of oil people.

It was a wet night of autumn,

when it came to my mind to make myself a man of oil.

That was it: a wet night of autumn

and God wanted me to quickly become a man of oil

and my forces to fight the most evil men.

I will sing the village I lived in first

and in which my hands and my soul were dirty

as much as they could get dirty.

I'm gonna sing the Buștenari men, the terrible and monstrous village of Buștenari,

in which every stone speaks of me and of my crimes,

in which every woman can tell you how cynical and lying they are

and I will then sing the derricks that I shed money on, like old mistresses.

But even when I'm singing the village and I'm glorifying the drillers,

I will sing all of myself

and if I should glorify places I have not seen and women I have not loved,

I would just glorify also myself,

because in me there are struggling places I have not seen and women I have not loved,

and I was able to crush Him and remove Him out of my way without a pity,

as He says in the Bible, that you must strike the serpent's head

as I crushed the head of the man who trusted me:

I remember:

I closed my eyes, I said "Oh, God!" and I struck

and then I have strucked several times without closing my eyes and no longer saying "Oh, God!"

and when I came out I was proud to see my heart beating regularly.

So it was every time:

my heart beat regularly

And that made me trust myself;

And I am sure that the laws of nature are with me and that I am right.

Somebody embroidered the doily.
Somebody waters the plant,
or oils it, maybe. Somebody
arranges the rows of cans
so that they softly say:Esso—so—so—so
to high-strung automobiles.
Somebody loves us all.